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Alioramus
| image = Alioramus2.jpg | image_caption = An artist's interpretation of Alioramus | image_width = 240px | regnum = Animalia | phylum = Chordata | classis = Sauropsida | clade1 = Dinosauria | superordo = Theropoda | superfamilia = Tyrannosauroidea | familia = Tyrannosauridae | subfamilia = Tyrannosaurinae | tribus = Alioramini | genus = †''Alioramus'' | genus_authority = Kurzanov, 1976 | type_species = Alioramus remotus | type_species_authority = Kurzanov, 1976 | subdivision_ranks = Referred species | subdivision = * Alioramus remotus Kurzanov, 1976 * Alioramus altai Brusatte et al., 2009 * Alioramus sinensis? (Lü et al., 2014) Carr et al., 2017 | synonyms = *''Qianzhousaurus? Lü ''et al., 2014 }} Alioramus (/ˌælioʊˈreɪməs/; meaning 'different branch') is a genus of tyrannosaurid theropod dinosaurs from the Late Cretaceous period of Asia. The type species, A. remotus, is known from a partial skull and three foot bones recovered from Mongolian sediments which were deposited in a humid floodplain about 70 million years ago. These remains were named and described by Soviet paleontologist Sergei Kurzanov in 1976. A second species, A. altai, known from a much more complete skeleton, was named and described by Stephen L. Brusatte and colleagues in 2009. Its relationships to other tyrannosaurid genera are unclear, with some evidence supporting a hypothesis that Alioramus is closely related to the contemporary species Tarbosaurus bataar. Characteristics Alioramus were bipedal like all known theropods, and their sharp teeth indicate that they were carnivores. Known specimens were smaller than other tyrannosaurids like Tarbosaurus bataar and Tyrannosaurus rex, but their adult size is difficult to estimate since both species are known only from juvenile or sub-adult remains. The recent discovery of Qianzhousaurus indicates that it belongs to a distinct branch of tyrannosaur. The genus Alioramus is characterized by a row of five bony crests along the top of the snout, a greater number of teeth than any other genus of tyrannosaurid, and a lower skull than other tyrannosaurids. |} Alioramus_06.jpg imagesCAJQU1DJ.jpg imagesCAX1QT61.jpg Untitled.png hhhg.jpg hgf.jpg tarbobaby.jpg Alioramus.png|An artist's representation of Alioramus. DAK Alioramus.jpg Ak dinos 6.jpg Well now you're num-num!.jpg Alioramus remotus Alioramus remotus was estimated at in length when originally described by Sergei Kurzanov in 1976. Kurzanov, however, did not correct for lengthening of the skull by deformation during fossilization, which may indicate a shorter overall body length for this individual. If this specimen is a juvenile, then adult Alioramus would have reached greater lengths, but no confirmed adult specimens are known. The skull of A. remotus was approximately long. In general, it is long and low, a shape typical of more basal tyrannosauroids and juveniles of larger tyrannosaurids. The premaxillary bones at the tip of the snout in Alioramus remotus have not been found, but are taller than wide in all tyrannosauroids for which they are known. The nasal bones are fused and ornamented with a row of five irregular bony crests that protrude upwards from the midline, where the nasal bones are sutured together. These crests all measure more than tall. At the back of the skull there is a protrusion, called the nuchal crest, arising from the fused parietal bones, a feature shared with all tyrannosaurids. In Alioramus, the nuchal crest is greatly thickened, similarly to Tarbosaurus and Tyrannosaurus. Like the rest of the skull, the lower jaw of Alioramus was long and slender, another possible juvenile characteristic. As in Tarbosaurus, a ridge on the outer surface of the angular bone of the lower jaw articulated with the rear of the dentary bone, locking the two bones together and removing much of the flexibility seen in other tyrannosaurids. Other tyrannosaurids had four premaxillary teeth, D''-shaped in cross section, on each side. Including 16 or 17 in each maxilla, and 18 in each dentary, ''Alioramus had 76 or 78 teeth, more than any other tyrannosaurid. The braincase of A. altai was intermediate between the basal theropod and avialan conditions. The rest of the skeleton of Alioramus remotus is completely unknown except for three metatarsals (bones of the upper foot), but the discovery of A. altai, which is known from substantially more complete remains, has shed light on the anatomy of the genus. Alioramus altai Paleontologists have long classified Alioramus within the superfamily Tyrannosauroidea, but because its remains were for many years poorly known, a more precise classification had remained elusive until the discovery of A. altai. A cladistic analysis published in 2003 found Alioramus could be further classified into the family Tyrannosauridae and the subfamily Tyrannosaurinae, alongside Tyrannosaurus, Tarbosaurus and Daspletosaurus. A 2004 study supported this result but suggested it was equally probable that Alioramus belonged outside the family Tyrannosauridae entirely, with its supposed juvenile characters actually reflecting a more basal position within Tyrannosauroidea. Another study omitted Alioramus altogether due to the only specimen's fragmentary nature. The discovery of A. altai in 2009 confirmed the placement of the genus within the Tyrannosaurinae. Tarbosaurus and Alioramus shared several skull features, including a locking mechanism in the lower jaw between the dentary and angular bones, and both lacked the prong of the nasal bones which connected to the lacrimal bones in all other tyrannosaurids except adult Daspletosaurus. The two genera may be closely related, representing an Asian branch of the Tyrannosauridae. Some specimens of Tarbosaurus have a row of bumps on the nasal bones like those of Alioramus, although much lower. The long and low shape of the only known Alioramus remotus skull indicated that it was immature when it died and might even have been a juvenile Tarbosaurus, which lived in the same time and place. The more prominent nasal crests and much higher tooth count of Alioramus, however, suggested it was a separate taxon, even if it is known only from juvenile remains, confirmed by the discovery of A. altai. Specimens identified as immature Tarbosaurus have the same tooth count as adults. Cladogram Recently a cladogram has been published finding Alioramus just outside Tyrannosauridae. Below is the cladogram by Loewen (2013). }} |2= |2=Tyrannosauridae }} }} }} }} }} }} }} }} }} However, a few later studies have found Alioramus to lie inside Tyrannosaurinae with Qianzhousaurus in a separate tribe, Alioramini. The phylogeny below is from the analysis by Stephen L. Brusatte & Thomas D. Carr (2016). |label2=Tyrannosaurinae |2= }} |2= |2= |2= }} }} }} }} }} }} }} Discovery and naming The holotype (PIN 3141/1) of Alioramus is a partial skull associated with three metatarsals. A joint Soviet-Mongolian expedition to the Gobi Desert in the early 1970s found these remains at a locality known as Nogon-Tsav in the Mongolian province of Bayankhongor. Alioramus was named and described by Russian paleontologist Sergei Kurzanov in 1976. Its crests and low skull profile looked so different from other tyrannosaurids that Kurzanov believed his find was far removed from other members of the family. Accordingly, he gave it the generic name Alioramus, derived from the Latin alius ('other') and ramus ('branch'), and the specific name A. remotus, which means 'removed' in Latin. Alioramus is known from the holotypes of A. remotus and A. altai. Prehistoric Asia n aimag (province) where Alioramus remains were discovered.|link=w:c:history:Prehistoric Mongolia]] The stage in (72.1 to 66 million years ago), as preserved in the and at , was characterized by a wetter and more humid climate compared with the semi-arid environment preserved in the earlier, underlying Barun Goyot and s. The Beds of Nogon-Tsav are considered to be the same age as the . This has never been dated radiometrically, but the present in the fossil record indicate it was probably deposited at the end of the Late Cretaceous in Maastrichtian. Nemegt sediments preserve s, large river channels and soil deposits, but caliche deposits indicate periodic droughts. This environment supported a more diverse and generally larger dinosaur fauna than in earlier times. Kurzanov reported that other theropods, including , s and s were discovered at the same locality, but these remains have never been reported in detail. If the Nogon Tsav fauna was similar to that of the Nemegt Formation, theropods, as well as s, s and s would also have been present. n s were also potential prey for predators in the Nemegt.. A recent paper describing a new species of Daspletosaurus, D. horneri, has suggested that Qianzhousaurus is the same genus as Alioramus, just a different species.. If this is the case, then Alioramus was also present in Southern China. In popular culture * Alioramus was supposed to appear in the video game Jurassic Park: Operation Genesis but was cut. * In the enhanced-motion vehicle attraction Countdown to Extinct AKA Dinosaur at Disney's Animal Kingdom theme park, an Alioramus is announced by an on-board computer, and is seen digging in the ground. As the vehicle nears the rooting dinosaur, it raises up to reveal a smaller animal in its mouth, which it proceeds to swallow as the prey kicks it hind legs and lashes with its tail, to no avail. Both creatures are brought to life through Audio-Animatronics. Gallery Alioramus/Gallery See also * Timeline of tyrannosaur research References External links *''Alioramus remotus'' at DinoData.org *''Alioramus remotus'' at The Theropod Database *[http://web.archive.org/web/20070110004450/http://www.paleograveyard.com/alioramus.html Skull image of Alioramus] at The Grave Yard *[http://www.pnas.org/content/106/41/17261/F3.large.jpg Illustration showing the pieces found of Alioramus altai.] Category:Tyrannosaurids Category:Saurischia Category:Dinosaurs of Asia Category:Carnivores Category:Large Carnivores Category:Coelurosaurs Category:Archosaurs Category:Cretaceous extinctions Category:Taxa named by Sergei Kurzanov Category:Fossil taxa described in 1976 Category:Mongolian dinosaur Category:Dinosaur King creatures Category:Late Cretaceous Dinosaurs Category:Small Carnivores Category:Jurassic Park: Operation Genesis